Bently Nevada 3500/40M Proximitor Monitor 4-Channel Module

The Bently Nevada 3500/40M Proximitor Monitor (P/N 143488-01) is a four-channel monitoring module designed for machinery protection and condition monitoring within the 3500 Machinery Protection System. It accepts signals from proximity probes to measure radial vibration, thrust position, differential expansion, eccentricity, and REBAM parameters. Furthermore, it provides programmable alarm functions, measurement status indicators, and buffered transducer outputs.

Monitoring Functions

The 3500/40M processes proximity probe signals to monitor shaft vibration and relative machine component positions. Its four input channels support several measurement configurations, depending on the selected monitoring function and application requirements.

Supported monitoring functions include:

• Radial Vibration: Measures shaft vibration relative to the proximity probe mounting position.
• Thrust Position: Monitors axial shaft displacement to identify changes in thrust position.
• Differential Expansion: Measures relative displacement between machine components.
• Eccentricity: Monitors shaft surface displacement associated with eccentricity.
• REBAM: Supports REBAM monitoring, including programmable spike frequency measurement.

In addition, the module provides programmable alarm setpoints and delays. This allows maintenance personnel to configure Alert and Danger responses according to the monitored variable and equipment protection requirements.

Inputs and Signal Conditioning

The monitor accepts signals from one to four proximity probes. Its input impedance is 10 kOhm under standard configuration and 50 kOhm for TMR applications.

The frequency response varies according to the selected measurement function. For example, radial vibration measurements support a direct frequency response from 4 Hz to 4 kHz, while REBAM spike measurements provide a programmable range.

Alarm Configuration and Measurement Accuracy

The module supports alarm setpoints from 0% to 100% of full scale. Alert and Danger delays can be configured independently, allowing the monitoring system to distinguish between different alarm response requirements.

Furthermore, the measurement accuracy is specified as +/-0.33% typical and +/-1% maximum. Alarm accuracy is +/-0.13% of the desired value.

Technical Specifications

Status Indication and Buffered Outputs

The front-panel LED indicators provide visual information about module operation and communication status. The OK, TX/RX, and Bypass indicators help maintenance personnel identify operating conditions and check the module status during troubleshooting.

Meanwhile, the buffered transducer outputs provide access to the monitored probe signals. The specified output voltage is -24 VDC, with a 550 Ohm impedance. These outputs support signal access for external monitoring and diagnostic equipment.

Frequently Asked Questions

Q: How many proximity probes can the Bently Nevada 3500/40M support?

A: The module provides four monitoring channels and accepts signals from one to four proximity probes. The actual channel configuration depends on the selected monitoring functions.

Q: What measurement functions does the 3500/40M support?

A: It supports radial vibration, thrust position, differential expansion, eccentricity, and REBAM monitoring. The applicable frequency response depends on the selected measurement function.

Q: What is the difference between the standard and TMR input impedance?

A: The specified input impedance is 10 kOhm for the standard configuration and 50 kOhm for TMR applications. Confirm the required system configuration before selecting the module.